The heat-source chip as mentioned above is obtained by cutting a continuous heat-source rod into a specified length. As shown in the specification of Japanese Patent No. 3472591, for example, the heat-source rod comprises an extrusion-molded article obtained by extrusion-molding a combustible fuel material into a rod-like shape, and a heat-insulating web wrapped around the extrusion-molded article. The heat-insulating web is made of glass fiber.
More specifically, the extrusion-molded article is fed to a wrapping section immediately after made, and therefore still in a wet or soft state, continuously wrapped in the heat-insulating web at the wrapping section and thereby formed into a heat-source rod. Then, the heat-source rod is fed to a cutting section, and at the cutting section, cut into a specified length, so that the above-mentioned heat-source chip is obtained. Thus, the heat-source chip comprises a fuel core formed from part of the extrusion-molded article, and a heat-insulating sheath formed from part of the heat-insulating web and enveloping the fuel core. The heat-source chip is then combined with other constituent elements so that the heat-source chip and other constituent elements form a substitute smoking article similar to a cigarette.
The heat-source chip, or more exactly, the extrusion-molded article needs to have burning characteristics suitable for the substitute smoking article. In this view, the extrusion-molded article has a through-hole formed in the center thereof, and a plurality of axial grooves formed in the cylindrical surface thereof. The axial grooves are arranged at equal intervals in the circumferential direction of the extrusion-molded article.
Meanwhile, the heat-insulating sheath of the heat-source chip needs to securely envelop the heat-source core and prevent the heat-source core from falling off the substitute smoking article. Thus, the manufacturing machine disclosed in the above-mentioned patent document includes a distribution roller. The distribution roller is disposed upstream of the wrapping section, and applies water onto the heat-insulating web as a bonding inducing agent before the heat-insulating web is fed to the wrapping section. The water applied dissolves pectin used in the heat-insulating web as a binder, and the pectin dissolved functions as an adhesive for bonding the extrusion-molded article and the heat-insulating web together. Specifically, the distribution roller applies water onto the heat-insulating web in the form of a streak extending along the longitudinal direction of the heat-insulating web, so that pectin dissolved forms a glue rail on the heat-insulating web.
As mentioned above, the extrusion-molded article has a plurality of axial grooves in the cylindrical surface. Thus, when the extrusion-molded article is wrapped in the heat-insulating web in the wrapping section, the glue rail on the heat-insulating web may coincide with one of the axial grooves. In this case, the glue rail is not in contact with the cylindrical surface of the extrusion-molded article and therefore does not effectively function as an adhesive for bonding the extrusion-molded article and the heat-insulating web together.
If a heat-source chip is obtained from a heat-source rod manufactured this way, the heat-source chip is defective with insufficient bonding between the fuel core and the heat-insulating sheath, and a substitute smoking article with such heat-source chip incorporated is also defective. If a shock is applied to such defective substitute smoking article in the axial direction during transportation or when it is held in a consumer's hand, the shock may cause axial shift of the fuel core of the heat-source chip. As a result of such axial shift, the fuel core protrudes from an end of the heat-insulating sheath, namely an end of the substitute smoking article, or plunges toward the constituent element adjacent to the heat-source chip within the substitute smoking article. Such protrusion or plunge of the fuel core makes the smoking of the substitute smoking article difficult.
In order to avoid this problem, it is conceivable to increase the number of glue rails formed on the heat-insulating web, or increase the width of the glue rail. In either case, however, a large amount of water is applied onto the heat-insulating web, so that an increased amount of water penetrates into the cylindrical surface of the extrusion-molded article, which decreases the hardness of the outer surface of the extrusion-molded article to a great degree.
When fed to the wrapping section, the extrusion-molded article is still in a wet and soft state and therefore contains a large amount of water. If, in addition to this water contained, a large amount of water penetrates into the extrusion-molded article from the heat-insulating web, the extrusion-molded article cannot maintain the external shape thereof. Thus, when the extrusion-molded article is wrapped in the heat-insulating web or when the heat-source rod is cut, the axial grooves of the extrusion-molded article may be deformed, or crushed and blocked. Deforming or crushing the axial grooves like this reduces the flow-passage cross-sectional area of the axial grooves to a great degree, so that the heat-source chip cannot have burning characteristics required.
The primary object of this invention is to provide a manufacturing machine and manufacturing method capable of ensuring sufficient strength of bonding between the extrusion-molded article and the heat-insulating web and imparting desired burning characteristics to the heat-source rod, and therefore, to the heat-source chip.